1. Field of Invention
The present invention relates to semiconductor devices. More specifically, the invention relates to a semiconductor device made by forming functional elements on a first substrate, separating an element chip including at least one functional element, transferring the element chip to a second substrate, and connecting first pads composed of a conductive material and disposed on the element chip to second pads composed of a conductive material and disposed on the second substrate. Moreover, the invention relates to a semiconductor device made by forming functional elements on a first substrate, separating an element chip including at least one functional element, transferring the element chip to a third substrate, transferring the element chip to a second substrate, and connecting first pads composed of a conductive material and disposed on the element chip to second pads composed of a conductive material and disposed on the second substrate.
2. Description of Related Art
In related art semiconductor devices, such as electronic circuits including functional elements, e.g., thin-film transistors or organic electroluminescent elements, interconnections between the functional elements, and supporting substrates, the functional elements can constitute only part of the whole, the rest being the interconnections and supporting substrates. When this type of semiconductor device is produced in one manufacturing process whereby the functional elements, the interconnections, and the supporting substrates are integrally formed, a highly advanced complicated manufacturing process is necessary to produce highly functional elements. This generally increases the manufacturing cost. However, no complicated manufacturing process is necessary to produce interconnections and supporting substrates, and the manufacturing cost thereof is low. The manufacturing cost of the semiconductor device as a whole can be averaged out and decreased if functional elements are manufactured in a process separate from that of manufacturing interconnections and supporting substrates, and subsequently installed at only required positions.
In view of the above, the related art also includes semiconductor devices that are made by forming functional elements on a first substrate, separating an element chip including at least one functional element, transferring the element chip to a second substrate, and connecting first pads composed of a conductive material and disposed on the element chip to second pads composed of a conductive material and disposed on the second substrate. The related art also includes semiconductor devices made by forming functional elements on a first substrate, separating an element chip including at least one functional element, transferring the element chip to a third substrate, transferring the element chip to a second substrate, and connecting first pads composed of a conductive material and disposed on the element chip to second pads composed of a conductive material and disposed on the second substrate. The related art also includes electrooptic apparatuses, such as a display apparatus that use these semiconductor devices. In this manner, the functional elements can be placed only at the required positions. When averaged out, the manufacturing cost of the semiconductor device as a whole can be reduced. In order to perform the separating and transferring processes, laser ablation or an adhesive agent can be used, as disclosed in (T. Shimoda, et al., Techn. Dig. IEDM 1999, 289; S. Utsunomiya, et al., Dig. Tech. Pap. SID 2000, 916; T. Shimoda, Proc. Asia Display/IDW '01, 327; and S. Utsunomiya, et al., Proc. Asia Display/IDW '01, 339).